Truck box cap exterior surface



FIG. 1 is a front and left side perspective view of a truck box cap exterior surface showing my new design;

FIG. 2 is a rear and left side perspective view thereof;

FIG. 3 is a left side view thereof, it being understood that the side opposite to that shown is a mirror image thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a rear view thereof; and,

FIG. 6 is a top view thereof.

The broken line showing throughout the drawings is for illustrative purposes only and forms no part of the subject design.

It will be understood that the bottom of the truck box cap exterior surface is plain and unornamented. 

The ornamental design for a truck box cap exterior surface, as shown and described. 